Fall 2021 crab population monitoring: mid-marsh and creek bank abundance based on crab hole counts at GCE marsh, monitoring sites 1-10

This data set is the Fall 2021 estimate of crab densities at the GCE-LTER marsh sites used for population monitoring. Crab abundance was determined by counting the number of crab holes within a 625 cm^2 quadrat and converting the counts to number per square meter. Counts were made in the mid-marsh and creek bank zones (n = 4 per zone) at GCE sites 1 through 10. Note that this census method does not differentiate which species made a particular hole and therefore only estimates total burrowing crab abundance, potentially including species Uca pugnax, Uca minax, Uca pugilator, Armases cinereum, Eurytium limosum and Sesarma reticulatum. Crab holes that are not actively maintained are quickly covered by tidal activity and other sediment disturbances, therefore plugged holes were assumed to be unoccupied and excluded from the counts.

本数据集为2021年秋季GCE-LTER沼泽站点的蟹类密度估算结果，该类站点用于蟹类种群监测。蟹类丰度通过计数625平方厘米样方内的蟹洞数量，并将计数结果转换为每平方米的个体数进行计算。调查覆盖GCE第1至10号站点的潮间带中部与溪岸带，每个区域设置4个重复样方（n=4）。需注意，本次普查方法无法区分单个蟹洞的造洞物种，因此仅能估算穴居蟹类的总丰度，潜在涵盖物种包括紧招潮蟹（Uca pugnax）、狭颚招潮蟹（Uca minax）、大西洋招潮蟹（Uca pugilator）、灰臂蟹（Armases cinereum）、宽额泥蟹（Eurytium limosum）以及网纹相手蟹（Sesarma reticulatum）。未被持续维护的蟹洞会迅速被潮汐活动与其他沉积物扰动所覆盖，因此本研究将堵塞的蟹洞视为未被占据，并将其从计数中排除。